The Art
of Lossless
Data Compression
vol. 18b

Here are the results of tests performed in September 2000 to compare
lossless compression of "binary" files by all known good enough programs
developed for such purpose, including RK, DC, YBS, Bzip2, IMP, RAR and 7-zip.
See Archive Comparison Test by J.Gilchrist for more details: http://act.by.net
If anybody wants to start or continue such tests,
or can suggest some other sets of files, or other compression programs,
(not sources or algorithm descriptions, executable programs only)
or knows we have missed something important,
(some new fantastic technology, an algorithm or even a program capable
of lossless compression of up to 1000:1 etc.)
please let us know immediately: artest@hotmail.ru Thank you!

WARNINGS:

ACB refuses to take files shorter than 257 bytes.
About 400 such files were processed with "rar a -m0 name.acb name.bin"
(see do_acb_u.bat and do_acb_r.bat).
BA 1.00beta can't losslessly decompress
any file compressed with -f ,
49 files compressed with any option
(astronmy\CRLFTX~1.bin, GFEMER~1.bin, MIRAIN~1.bin, NIL_~1.bin, NIL~1.bin
README~7.bin, SAOSOU~2.bin, STARVI~6.bin, UNIV00~1.bin, ZEROME~1.bin ;
chem\ARCHIV~3.bin, ARCHIV~4.bin, DISK1_~1.bin, DISPOS~3.bin, KHEMCF~1.bin etc.)
It says nothing like "CRC fails".
DC 0.99.158b fails to decompress HLPCOPY..bin, but only if you compress
with "-mb5" switch and [<output>] filename like "any.dc5".
Says nothing like "CRC fails".
RK 1.03b1 was unable to correctly decompress 55 files
compressed with "-mf2" or "-mf3", reporting
> ERROR 303: CRC check failed.
All are .htm, like font\README~3.BIN , and only one byte differs
after extraction, and no problems if compressed with "-mx2" in all 55 cases.
Unfortunately, 64Mb RAM is not enough to run RK 1.03 with "-mx3":
endless swapping (virtual memory to hard disk) when compressing some binary
files (but no swapping on text files).
ZZip 0.35e can't decompress only one file, mapping\DEMOMP~1.bin .
With any (compress) options, "ZZip error : CRC error".
UFA and 777 can't find files with long names,
if you give short versions of that long names,
and they can't process files with two or more extensions.
BIX, third version of UFA, was tested instead.
Problems in all other 15 compressors were not found.
File order (in binaries.dat) is wrong in some columns:
- RK and BOA understand only long filenames, not short versions,
and files get different short versions of names when extracted.
- in \mapping\ directory, files were not sorted by DIR/on command:
"Too many files, directory not sorted".
The LATEST RELEASE, and fifteen previous versions of these tests can be found
at http://geocities.com/SiliconValley/Bay/1995/ and http://artest1.tripod.com/